In order to understand the adhesion characteristic of pathogenic Vibrio fluvialis to the skin mucus of Epinephelus awoara, isotope tracer method was introduced to investigate the bacterial adhesion of the pathogen to the mucus after different treatment. A significant enhancement in the adhesion rate of V. fluvialis to the skin mucus was observed after heating the mucus at 40, 60 and 80 ℃ for 10 min. However, an extremely significant inhibition in the bacterial adhesion was observed when the mucus had been heated at 100 ℃ for 10 min. No remarkably effect on the bacterial adhesion was found after treating the mucus with protease K and trypsin, whereas the bacterial adhesion was extremely significant enhanced by treating the mucus with periodic acid; It was observed that pretreating the mucus with glucose, mannose, mannitol and maltose enhanced the bacterial adhesion extremely significantly, and other 3 carbohydrates enhanced the bacterial adhesion significantly; while galactose could not enhance the bacterial adhesion significantly. Surface extract of V. fluvialis with high concentration inhibited the bacterial adhesion significantly, whereas the surface extract with relative low concentration enhanced the bacterial adhesion. 3 protein peaks were obtained by fractionating the mucus with a Sephadex G-100 column, and the strong adhesion was observed to the first peak. The results indicated that: pathogenic V. fluvialis adhere to the skin mucus of E. awoara strongly; there were specific adhesive receptors within the mucus; the adhesive receptors were likely to be macromolecules with relative stability to heating and protease.